Process and apparatus for the production of fiber fleece



April 26, 1966 L. HARTMANN PRoCEss AND APPARATUS PoR THE PRODUCTION oFFIBER FLEECE Filed Aug. 6, 1965 ARME-RKK' INVENTOR LUDWIG HA RTMA NNUnited States Patent 3,247,557 PROCESS AND APPARATUS FR Tim ERG- DUCTENF FIBER FLEECE Ludwig Hartmann, Lutzelsachsen, Bergstrasse, Germany,assignor to Carl Freudenberg Kommanditgesellschaft AuAktien,Bergstrasse, Germany Filed Aug. 6, 1963, Ser. No. 399,389 Claimspriority, application Germany, Aug. 6, 1962, n 37,534 18 Claims. (Cl.28-1) Fiber batts of fleeces, such as those used in the manufacture ofmatting, filter materials or materials to be used as supports foracoating of plastics, should preferably have the fibers in a randomarrangement, thereby achieving equal strengths in various directions. Inthe prior manufacture of these batts, such random arrangement isproduced, for example, by the superposition of a plurality of webs, sothat Ion the average a random distribution of fiber orientations isachieved. One disadvantage of these materials, however, consists in thefact that the individual layers tend to come apart. This characteristiccan be overcome, however, lby the present invention.

The manufacture of the fiber fleeces is performed in the process of thisinvention by vertical and horizontal deposition of the fibers andmatting them together in the manner of a cocoon. The fibers or filamentsused in building up the fiber fieeces are blown in an airstream tobetween a pair of suction rolls. The suction rolls can be disposed oneover the other, for example, the distance between the rollscorresponding approximately to the desired thickness of the ber fleece.The fibers or filaments, as the case may be, are carried in a current ofgas or vapor of the width of the desired fleece against the pair ofsuction rolls in such a manner that, in the course of time, the fiberspour into the roller -gap over its entire width. Due to the turbulenceof the airstream, the' fibers or filaments begin, at a predetermineddistance in front of the rolls, to swing and oscillate back and forth.They are therefore seized in irregular order, sometimes by the uppersuction roll and sometimes by the lower one, as they advance to betweenthe pair of rolls. Since the rate of delivery of the fibers or filamentsis a multiple of the rate at which the fiber batt is withdrawn, a shortlength of an individual fiber is drawn up, for example, by the uppersuction roll, and due to the up and `d'own oscillation of the airstreamcarrying the fibers, an adjacent part of the fiber is seized in the nextmoment by a lower suction roll and thus the fiber is disposed in avertical orientation. Since the airstream oscillates not only up anddown but also back and forth, in the next moment another fiber is laidcrosswise at a certain angle to the previously deposited fiber. Thisprocess is repeated in rapid succession over the entire fiber catchingwidth and height, so that a random, homogeneous fiber structure isproduced. Especially when endless fibers are used for the production ofthe fleece, the orientation of the deposit is constantly changingdirection and fiber fleeces of any desired thickness can be produced.

Thus, the process of the invention comprises advancing a plurality offilaments along a path leading to between spaced iieece forming membersso that the filaments move to adjacent and on to between said members.Gas streams are passed in a direction extending transverse to the pathand the gas streams have a component perpendicular to the path so thatmovement of the filaments as they pass to between the fleece formingmembers is disrupted and individual filaments are caused to be dispersedin back and forth random array with respect to the fleece formingmembers. There are at least two such gas streams and the perpendicularcom- 3,247,567 Patented Apr. 26, 1966 ponents of' said streams aredisposed in opposite direction. The filaments are collected as a fleecebetween the fleece forming members and the fleece so formed is movedaway from between the fleece forming members. Desirably, the directionof movement of the gas streams is such that the said perpendicularcomponents thereof are in a direction away from the path of thefilaments toward the fleece forming members and of the fleece beingformed.

The filaments advanced to the fleece forming members can be produced byspinneret's, and the filaments can move directly from the spinnel'ets tothe fleece forming members so that continuous productionV of fleece fromfilament forming material, such as multiple polymers, can be achieved.

The procedure and apparatus of co-pendin-g application SerialNo.341,489, filed January 27, 1964, can be utilized for the production ofthe filaments. In this procedure a plurality of filaments issue from alike number of spinnerets and the filaments are distended by a vgasstream which impinges upon the filament forming material as it leavesthe spinneret. The gas stream which so impinges can be utilized,supplementedl if desired by further gas streams, to carry the filamentsto the fleece forming device of the invention. Thus the filaments aremoved from the spinneret head to a eece forming device as a rank offilaments. Entanglement is prevented by closely controlling the gasstream which entrains the filaments and carries them to the fleeceforming device. Operation in this manner provides monofilaments and itis desirable to practice the present invention with monofilaments.

The fleece forming device of the invention can comprise perforatedmembers disposed one on other side of the filament path and spaced aparta distance in excess of the filament thickness and equal tothe'thickness for the fleece to be produced. The gas streams utilized todisrupt the movement of the filaments can be drawn through theperforated members, or forced outwardly through these members so that asthe filaments advance toward and between the perforated members, theirmovement is modified in a manner to provide a random array.

The invention is fully described in reference to the accompanyingdrawing, wherein:

FIG. 1 -is a perspective view schematically indicating the combinationof a spinneret and a fleece forming device;

FIG. 2 is a schematic side elevation of a fleece forming device;

FIG. 3 is a plan view of a portion of the device shown in FrG. 2; y

FIG. 4 is an elevation View taken along line 4 4 in FIG. 3.

Referring to the drawings, a rank 6 made up of a plurality ofmonofilaments 7 disposed generally in a plane and issuing from spinnerethead S, advance over a path extending from the spinneret head 8 towardthe fleece forming device 9. The spinneret head 8 includes gasdelivering means 1) and 11, which means discharge a gas stream toimpinge and entrain the filament forming mate*- rial as it issues fromthe spinneret head 8. This gas stream, supplemented if desired by othergas streams (not shown) serves to entrain and advance the filaments toadjacent the fleece forming device 9,

The fleece forming device 9 is made up of an upper endless screen 12 anda lower endless screen 13. The upper endless screen 12 passes over theend wheel 14, which is driven in the direction indicated by the arrow 15by drive gear 16, which intermeshes in driving relation with the gear 17mounted on the end of the axle of the wheel 14. At the other end, theperforated screen 12 passes over idler wheel 1S. In a similar manner,the lower endless screen 13 passes over the drive wheel 19 and idlerwheel 20.

As can be best seen in FIG. 3, Within the idler wheels 18 and 29 are,respectively, suction chambers 21 and 22, and each of these suctionchambers has an intake opening, respectively, 23 and 24. As is indicatedin FIG. 3 and FIG. 4, the suction chambers are fixedly mounted on theaxles of the wheels in which they are, respectively, disposed. Thus, asis indicated in FIG. 3, the suction chamber 21 is a hollow chamberdisposed about the axle 25 of the idler Wheel 13. This axle is mountedin journal blocks 26. The suction chamber includes intake 27 whichcommunicates with one end of the suction chamber, and this intake isfixedly mounted on the support 28 (FIG. 4). A conduit 29 communicatesthe intake chamber with a vacuum source.

As is indicated in the drawing, particularly in FIG. 1 and FIG. 2, thefilaments 7 in the rank 6 advance toward the fleece forming device 9 andduring this advance are, individually, disposed in relatively straightlines. Suction is applied to the vicinity of the inlet to between theupper endless belt 12 and the lower endless belt 13, so that a gasstream is dra-wn along paths indicated by the arrows 30. Thus, gasstreams are provided in the vicinity of the inlet to the fleece formingdevice which have a Component perpendicular to the path of the filamentstoward the fleece forming device. Such gas streams occasion disruptionof the movement of the filaments since substantial turbulence is createdin the vicinity of the inlet. This causes successive portions of eachfilament to be shifted in direction so that the filaments extend up anddown and across to provide a random array which builds up into a fleeceof a thickness corresponding to the space of the runs of the endlessscreens disposed adiacent to each other.

While the invention has been described with respect to particularembodiments thereof, these embodiments are merely representative and donot serve to set forth the limits of the invention.

What is claimed is:

1. Process for the production of fiber fleeces which comprises:

(a) advancing a plurality of generally straight filaments along a pathleading to between spaced fleece forming members to adjacent saidmembers,

(b) passing gas streams in a direction extending transverse to the pathand having components perpendicular to the path to disrupt the movementsof the filaments to cause individual filaments to be disposed back andforth with respect to the fleece forming members, there being at leasttwo such gas streams, the said perpendicular components of which areopposite in direction,

(c) collecting the filaments disposed back and forth as aforesaid as afleece between the fleece forming members, and

(d) moving the fleece so formed away from the fleece forming members.

2. Process according to claim 1, the lperpendicular components of eachof said two gas streams being away from said path.

3. Process according to claim 1, wherein the filaments are advanced toadjacent said fleece forming members by a gas stream moving along saidpath toward said fleece forming members.

4. Process according to `claim 1, wherein said fiarnents aremonofilaments. A

5. Process for the production of fleeces which cornprises: n

(a) advancing a plurality of generally straight filaments along a pathleading to between spaced, perforated fieece forming members to adjacentsaid members,

(b) moving said fleece forming members in the direction of said advanceofthe filaments, l

(c) passing gas streams in a direction extending transverse to the pathand having components perpendicular to the path to disrupt the movementof the filaments and cause individual filaments to `be dispersed backand forth with respect to the fleece forming members, there being atleast two such streams the said perpendicular components of said twostreams being in opposite direction, said gas streams being passedthrough the perforated fleece forming members,

(d) collecting the filaments disposed back and forth as aforesaid as afleece between the fleece forming members, and

(e) moving a fleece so formed away from between the fleece formingmembers.

6. Process according to claim 5, wherein the perpendicular ycomponent ofeach of said two gas streams is away from said path.

7. Process according to claim 5, wherein the filaments are advanced toadjacent the fleece forming members by a gas stream moving in thedirection of movement of the filaments toward the fleece formingmembers.

S. Process according to claim 5, wherein said filaments aremonofilaments.

9. In combination with means for spinning filaments and advancing thefilaments along a defined path, a fleece forming device comprising:

(a) perforated members disposed one on either side of the said path, andspaced from each other a distance in excess of the thickness of thefilaments and equal to the thickness of the fleece to be formed andmeans for moving said members in the direction of the advance of thefilaments along said path,

(-b) means for passing gas streams in a direction extending transverseto the path and having components perpendicular to the path to disruptthe movement of the filaments and as they pass to between the fleeceforming members to cause individual filaments to be dispersed back andforth with respect to the fleece forming members, said means for passingthe gas streams providing at least two gas streams the saidperpendicular components of which are opposite in direction, and

(c) means for directing the filaments in generally straight conditionalong a portion of said path to said gas streams.

10. Apparatus according to claim 9, the means for passing gas streams asaforesaid providing at least two of said gas streams to move away fromthe direction of advance of the filaments toward the fleece formingdevice.

11. Apparatus according to claim 9, wherein said perforated memberscomprise two endless belts.

12. In combination with means for spinning filaments and advancing thefilaments along a defined path, a fleece forming device, comprising:

(a) a perforated endless belt disposed on each side of said path with arun of each belt disposed alongside a portion of said path, the belts intheir endless paths turning into their respective runs at the sameposition along the path, said belts being spaced apart a distance inexcess of the thickness of the filaments and equal to the thickness ofthe fleece to be formed, and means for moving said belts so that saidruns thereof move along said path in a direction of advance of filamentsalong said path,

(b) means for passing gas streams in a direction extending transverse tothe path and having components perpendicular to the path to disrupt themovement of the filaments and as they pass to between the fleece formingmembers to cause individual filaments to be dispersed back and forthwith respect to the fleece forming members, said means for pass. ing thegas streams as aforesaid providing at least two such gas streams, thesaid perpendicular cornponents of which are opposite in direction, and

(c) means for directing the iilaments in generally straight conditionalong Ia portion of said path to said gas streams.

13. Apparatus according to claim 12, wherein said means for passing gasstreams is for providing gas streams moving away from the direction .ofadvance of filaments toward the eece forming device.

14. A device for forming a iieece from laments moving along a definedpath, comprising:

(a) perforated members disposed one on either side of the said path, andspaced from each other a distance in excess of the thickness of theiilarnents and equal -to the thickness ofthe fleece to be formed andmeans for moving said members in the direct-ion of the advance of thefilaments along said path,

(b) means for passing gas streams in a direction extending transverse tothe path and having components perpendicular to the path to disrupt themovement of the filaments and as they pass to between the eece formingmembers to cause individual laments to ibe dispersed back and forth withrespect to the fleece forming members, said gas supply means providingat least two gas streams the said Iperpendicular components of which`are opposite in direction, and

(c) means for directing the filaments in generally straight conditionalong a portion of said path to said gas streams.

15. Apparatus yaccording to claim 14, said two gas supply meansproviding gas streams moving away from the direction `of yadvance of theiilaments toward the eece forming device.

16. Apparatus according to claim 14, wherein said perorated memberscomprise two endless belts.

17. Apparatus for the production of ee-ces from filaments moving along adefined path, comprising:

(a) -a perforated endless belt disposed on each side of said path with arun of each belt disposed alongside a portion of said path, the belts intheir endless paths turning into their respective runs at the sameposition along the path, said belts being spaced apart a distance inexcess of the thickness of the filaments :and equal -to the thickness ofthe tieece to be formed, and means for moving said belts so that saidruns thereof move along said path in a direction of advance of filaments`along said path,

(b) means for passing gas streams in a direction extending transverse tothe path and having components perpendicular to the path to disrupt themovement of the filaments and as they pass to between the lieece formingmembers to cause individual filaments to be dispersed back and forthwith respect to the fleece forming members, said means for passing thegas streams as aforesaid providing at least two such gas streams, thesaid perpendicular components of which are opposite i-n direction, and

(c) means for directing the laments in generally straight conditionalong a portion of said path to said gas streams.

18. Apparatus according to claim 17, wherein said Y means for passinggas streams is for providing gas streams moving away from the directionof advance yof ilaments toward the eece forming device.

References Cited bythe Examiner UNITED STATES PATENTS 2,577,214 12/1951Slayter 161-72 2,586,774 2/ 1952 Bastian et al. 2,662,044 12/'195-3Marrison et al 161-72 2,878,547 3/1959 McMaster et al. 28-1 2,981,999 5/1961 Russell 28-1 3,044,145 7/ 1962 Tager et al t28- 1 DONALD W. PARKER,Primary Examiner.

9. IN COMBINATION WITH MEANS FOR SPINNING FILAMENTS AND ADVANCING THEFILAMENTS ALONG A DEFINED PATH, A FLEECE FORMING DEVICE COMPRISING: (A)PERFORATED MEMBERS DISPOSED ONE ON EITHER SIDE OF THE SAID PATH, ANDSPACED FROM EACH OTHER A DISTANCE IN EXCESS OF THE THICKNESS OF THEFILAMENTS AND EQUAL TO THE THICKNESS OF THE FLEECE TO BE FORMED ANDMEANS FOR MOVING SAID MEMBERS IN THE DIRECTION OF THE ADVANCE OF THEFILAMENTS ALONG SAID PATH, (B) MEANS FOR PASSING GAS STREAMS IN ADIRECTION EXTENDING TRANSVERSE TO THE PATH AND HAVING COMPONENTSPERPENDICULAR TO THE PATH TO DISRUPT THE MOVEMENT OF THE FILAMENTS ANDAS THEY PASS TO BETWEEN THE FLEECE FORMING MEMBERS TO CAUSE INDIVIDUALFILAMENTS TO BE DISPERSED BACK AND FORTH WITH RESPECT TO THE FLEECEFORMING MEMBERS, SAID MEANS FOR PASSING THE GAS STREAMS PROVIDING ATLEAST TWO GAS STREAMS THE SAID PERPENDICULAR COMPONENTS OF WHICH AREOPPOSITE IN DIRECTION, AND (C) MEANS FOR DIRECTING THE FILAMENTS INGENERALLY STRAIGHT CONDITION ALONG A PORTION OF SAID PATH TO SAID GASSTREAMS.